1. Field of the Invention
The present invention relates to a cutting-oil coater for applying cutting-oil to a workpiece or a tool during cutting and a cutting device.
2. Description of the Prior Art
Hitherto, cutting-oil has been applied to a target object, a tool, or the like in order to improve machining accuracy and to extend tool life. When applying oil in a state of droplet, cutting can be carried out with only a necessity minimum amount of oil, thus not only improving machining accuracy and productivity, but also leading to improving a working environment and the simplification of a plant and equipment.
FIG. 6 is a view showing the configuration of one example of a conventional cutting-oil coater. Reference numeral 50 denotes a spray feed device for feeding an oil spray (liquid fine particles of oil). The spray conveying device includes a container 51 forming a main body. The container 51 is provided with a spray discharge nozzle 52, an air discharge nozzle 53, a spray conveying pipe 54 and an oil feed port 55. The air discharge nozzle 53, which is used to feed the container 51 with air, is connected to a gas source 56. The flow rate of the discharged air can be regulated by an air flow rate regulating valve 58b. 
The spray conveying pipe 54 is used to convey oil spray inside the container 51 to the outside of the container 51. The oil spray is injected into the container 51 from a nozzle tip portion 52c of the spray discharge nozzle 52. The spray discharge nozzle 52 has a dual structure formed of a gas tube 52a and an oil tube 52b that extends inside the gas tube 52a. The gas tube 52a is connected to a gas source 56. The flow rate of discharging gas can be regulated by a gas flow rate regulating valve 58a. The oil tube 52b is connected to an oil pump 57. The flow rate of oil from the pump 57 can be regulated by an oil flow rate regulating valve 59.
At the nozzle tip 52c, oil fed from the oil pump 57 and gas fed from the gas source 57 are mixed with each other, and thus oil spray is produced and injected into the container 51. The air pressure from the spray discharge nozzle 52 is applied to the inside of the container 51, so that fine oil spray residing in the container 51 is affected by the pressure applied and is conveyed to the spray conveying pipe 54. Furthermore, the gas discharged from the air discharge nozzle 53 can increase the internal pressure in the container 51.
The oil spray passing through the spray conveying passage 54 finally is discharged from a tip 63 having a narrower diameter. Thereby, the flow velocity of the oil spray increases, and the oil spray is discharged in a state in which it is liquefied in a state of an oil droplet so that it can be attached to a workpiece. This discharged flow can be used as a lubricant in cutting.
The oil 62 inside the container 51 flows into the pump 57 via the oil feed port 55 and is used for producing oil spray. The oil 62 also includes the oil that has dropped inside the container 51 and has not flowed into the conveying passage 54. The container 51 also serves as an oil storage portion. Oil can be refilled into the container from an oil feed port 61 by uncapping an oil-refilling cap 60.
However, the above-mentioned conventional cutting-oil coater has following problems. As mentioned above, the container 51 serves as an oil storage portion, and the oil pump 57 and various regulating valves are also arranged together with the container 51. When such a device is attached to a machining tool, to take the convenience in oil-refilling or regulation of the flow rate into account, such a device is attached to, for example, a side of the machining tool that faces an aisle. Thereby, in general, the distance between the oil coater main body and a position for cutting is increased, and thus the total length of the conveying passage 54 also is increased.
In this case, since the conveying passage 54 is provided in accordance with the shapes of the various portions of the machining tool, the conveying passage 54 has a large number of bend portions between the container 51 and the discharge portion 63. The presence of the bend portions causes turbulence in the oil spray during conveying. As a result, a part of fine oil spray is liquefied. Such a liquefaction of the oil spray may cause clogging in the conveying passage 54, thus preventing the conveying of the oil spray.
One of the measures taken for solving such problems may be to take a specification of the shapes of the various portions at the side of the machining tool so that the bend portions in the conveying passage 54 are reduced. In this case, the specification of the machine tool is limited as well as the machining tool becoming larger. Furthermore, space for providing the machining tool has to be increased, which is not realistic.
Furthermore, if the coater itself is provided in the vicinity of cutting portion, the above-mentioned problem is solved. However, in this case, the oil supply becomes inconvenient and the regulation of the device or checking of operation becomes inconvenient. For example, when the coater is provided at a high place in the large size machining tool, work such as an oil supply becomes extremely difficult.
With the foregoing in mind, it is an object of the present invention to provide a cutting-oil coater capable of preventing the liquefaction of oil spray during conveying and improving the efficiency of work, for example, oil-refilling, etc. by forming a spray feed portion and an oil storage portion separately and enabling the arrangement position thereof to be regulated.
In order to achieve the above-mentioned object, a cutting-oil coater of the present invention includes a spray feed portion, an oil storage portion for storing oil to generate spray, an oil feed means for feeding oil in the oil storage portion to the oil spray feed portion, and a spray conveying passage for conveying the oil spray inside the spray feed portion to the outside of the spray feed portion, wherein the spray feed portion and the oil storage portion are formed separately from each other and can be remote arranged in different positions respectively, and the arrangement position can be adjusted. With such a cutting-oil coater, since the spray feed portion can be attached in the vicinity of the cutting portion and the oil storage portion can be disposed in a place where an oil-refilling work can easily be carried out, it is possible both to prevent liquefaction of the oil spray during conveying and to improve the efficiency of work such as an oil-refilling.
It is preferable that the above-mentioned cutting-oil coater further includes a return passage for allowing the oil in the spray feed portion to return to the oil storage portion. With such a cutting oil coater, oil can be reused.
Furthermore, it is preferable that the pressure inside the spray feed portion is higher than the pressure inside the oil storage portion, and the oil inside the return passage is conveyed to the oil storage portion due to the difference between the pressure inside the spray feed portion and the pressure inside the oil storage portion. With such a cutting-oil coater, since it is not necessary to use an oil pump etc. for conveying a returning oil and it is not necessary to use the gravity drop for return of oil, the degree of freedom in the arrangement of the return passage is enhanced.
Furthermore, it is preferable that an inlet of the return passage in the spray feed portion is an orifice with a narrower diameter with respect to the return passage. With such a preferred cutting-oil coater, it is possible to reduce the gas flow rate inside the spray feed portion while conveying oil to the oil storage portion.
It is preferable that the inlet of the return passage has a narrower diameter portion whose cross-sectional area is in the range from 0.05 mm2 to 0.15 mm2. With such a cutting-oil coater it is possible to prevent the gas in the spray feed portion from flowing into the return passage while conveying oil to the oil storage portion.
Furthermore, it is preferable that a cross-sectional area of the inlet of the return passage is variable. With such a cutting-oil coater, since it is possible to regulate the cross-sectional area of the inlet of the return passage in accordance with the internal pressure of the spray feed portion, for example, in a case where the internal pressure of the spray feed portion is increased, it is possible to suppress the gas from flowing into the inlet by reducing the cross-sectional area of the inlet.
Next, a cutting device of the present invention includes the above-mentioned cutting oil coater. With such a cutting device, since the spray feed portion can be attached in the vicinity of the cutting portion and the oil storage portion can be disposed in a place where an oil-refilling work can easily be carried out, it is possible both to prevent liquefaction of the oil spray during conveying and to improve the efficiency of work such as an oil-refilling.